How to Equalize Charge a flooded battery
Many experts recommend that batteries be equalized periodically, ranging from once a month to once or twice per year. The application determines the frequency of an equalizing charge. Essentially the more the battery is cycled, the greater the need for equalization. An Equalize charge (equalizing) should be used on flooded batteries when specific gravity readings vary +/-.015 from cell to cell on a fully charged battery.
Equalizing is an “over voltage - overcharge” performed on flooded lead-acid batteries after they have been fully charged to stimulate gassing and bubbling (essentially mixing) of the batteries' electrolyte (acid). It helps to eliminate acid stratification, a condition that occurs in all flooded batteries (the uneven distribution of acid), and sulfation (the buildup of sulphate crystals on the plates). These are two of many conditions that can reduce a flooded battery's overall performance and life.
Equalize charging should not be performed on AGM or GEL batteries. ”Balance Charge” modes are included in all Discover Industrial, Commercial and Electric Vehicle charges. Balance Charging for Discovers Semi-Traction AGM and GEL batteries looks to be similar to an equalize charge cycle for flooded batteries but is performed at specifically designed temperature-compensated voltage, time and current range.
- Verify the batteries are flooded type
- Remove all loads from the batteries
- Connect battery charger
- Set the charger to equalizing mode
- Start charging batteries
- Batteries will begin gassing and bubbling vigorously
- Take specific gravity readings every hour
- Equalization is complete when specific gravity values no longer rise during the gassing stage
- Battery voltage during an equalization charge should be allowed to rise to 2.65V per cell +/- .05V (8V on a 6-volt battery and 16 volts on a 12V battery)
NOTE: Many chargers do not have an equalization setting, so this procedure can’t be carried out.
WARNING – DO NOT EQUALIZE CHARGE GEL OR AGM BATTERIES! Equalizing is an “over voltage-over charge” performed on flooded lead-acid batteries after they have been fully charged to help eliminate acid stratification. It helps eliminate acid stratification and sulfation in all flooded lead-acid batteries. Acid Stratification is the #1 killer of flooded lead-acid batteries.
Laboratory-designed, specific to Discover, “Balance” charge algorithms have been designed and are included in all Discover recommended Industrial Commercial charges offered for sale wherever our Discover AGM and GEL VRLA DRY CELL products are sold. Visually the Balance Charging curve diagram is similar to a flooded equalize charge curve in its finishing voltage. Still, it is strictly controlled to promote proper active material conversion and not to promote gassing or bubbling of the acid to help reduce acid stratification, as in a flooded battery. Discover’s Balance charging algorithms are HIGHLY recommended for batteries being installed in strings, larger batteries using taller plate groups and/or with batteries constantly being subjected to high-rate deep discharges